Two men carry a heavy sack between them. It contains something very precious to both of them, and though they barely have the strength to lift it, the question of abandoning the sack does not even occour to them. Soon the men see a third man in the distance. The immediately bury the sack and join the new man, never to return to it.

Did they bury the sack because they no longer needed it? Or, perhaps, because it contained evidence for a heinous crime? That, in the absence of other men, they might also need to stay alive?

Were they in a desert? And they killed a man and took his water, etc. and were drinking that and eating him? (Or, perhaps, they were in a cold desert and could eat snow and the man?) And they saw a rescuer? So they quickly buried the evidence and rushed to the rescuer?

**************SPOILER************** This puzzle is based on the story of the football team whose plane crashed in the Andes. Without food, the survivors had to resort to eating those who died in the crash. When it became obvious that they weren't going to be rescued, the two fittest men took a supply of meat and trekked over the mountains in search of civilisation, but buried the food in shame when they found rescue.